found that the added momenta of the balls is the same whether
before or after impact, a fact useful in many calculations. In the
case of ordnance the total momentum is divided at explosion.
equally between gun and carriage on the one hand, and the shot
and charge on the other. Introducing a practical coefficient n,
Highest velocity | _ (weight of shot and charge) x (muzzle velocity) x IT
of recoil j ~~ (weight of gun and carriage)
the quantities being in Ibs. feet and seconds.
_ ivv . , f f .. wv ,
But $ = —~(PP- 473-4) •'• mean force of recoil = —- and
maximum force = mean force x 2.
Energy is the capacity to do work.—Potential Energy is
latent till some small change occurs to give it actual value: thus
the chemical energy in coal requires a small starting heat, and the
water in a high tank may be released by opening a small valve.
Kinetic Energy or energy due to motion, is always visible so to
speak, except in the case of molecular movement merely.
EXAMPLES OF ENERGY FORMS.
Energy of position.
(Capable of muscular exertion.)
( That due to separation of positively
\ and negatively-electrified bodies,
( as in frictiortal electricity.
fDxie to separate existence of
elements, as in gunpowder
Clock spring ^wound up
5, Electrical Energy
6. Chemical Energy